As shown in FIG. 1, a conventional fan frame 10 has a hollow containing space 11 therein for accommodating a fan rotor (not shown), and a base 12 is disposed in the containing space 11. The base 12 is integrated with the fan frame 10 as a whole by means of a plurality of ribs 12, and a hole between the ribs 12 is formed as a passage for air circulation. A driving device (not shown, and the operation relationship of fan rotor and driving device is not covered here due to their irrelevance to the present invention) is mounted on the base 12 for driving the fan rotor to rotate and operate.
If classified by type of material, the conventional fan frame can be approximately classified into two types, namely type 1 pertaining to a die-casting aluminum frame and type 2 pertaining to an plastic frame produced by injection modeling.
Due to higher material cost itself, the die-casting aluminum frame costs relatively more.
Although the material cost is relatively cheaper than the aluminum frame, the plastic frame produced by injection modeling has its intrinsic material issue, making the plastic frame hardly a substitution for the aluminum frame.
Here are some disadvantages of the plastic frame to be concluded and depicted in details.
(1) Uncontrollable dimension precision: In a cooling process after injection modeling of plastic frame, if the saturation pressure condition is not controlled well, the material is often prone to contraction and is thus subjected to an inferior dimension precision of the finished product.
(2) Inferior structure strength and heat resistance: As a result of inferior heat resistance and deteriorating strength of the plastic material at high temperature, the plastic fan frame is often deformed to further result in attrition between the rotating fan rotor and the fan frame from which the quality issues usually come, while the plastic frame is operated in a high-temperature environment.
(3) Confined development and design space: In consideration of the quality, the plastic frame usually maintains a fixed wall thickness to secure the overall strength of the fan frame, meaning that R & D people must give priority to reserve room for the wall thickness of the fan frame and the gap between the frame and the fan rotor while dealing with smaller cooling fan, and in turn indicating that the blade size of fan rotor shall be reduced. However, the blade size further directly relates to the overall heat dissipation performance of the cooling fan. As a consequence, the cooling fan designed and developed in such manner fails to effectively and obviously surpass its current performance.
(4) Limited cooling fan performance: When the blade size of the fan rotor is subjected to limitation, the air flow and fan speed of the cooling fan are also constrained so as to introduce a deficit to the entire performance.
As such, to completely tackle the inherent issue of the aforementioned fan frame, a fan frame structure with brand new idea shall be more aggressively conceived and developed to enhance its overall structure strength and heat resistance, and the structure strength decrease and deformation issues arising from a high-temperature environment are effectively prevented.